A current trend of new wireless integrated circuits exploits the advantage of millimeter wave radio frequencies, where the wavelength is short enough to enable antennas integrated on the die or in the package. The antenna and the connection to the antenna of these electronic devices become more important for radiation properties. Some of these integrated circuits use several antennas for beam steering (e.g. 16, 36, . . . ) and/or for multiple input multiple output MIMO (e.g. 4+4, . . . ) communication. These applications increase the demand of test systems capable of testing wireless dies or packaged chips.
Known systems carry out a conducted test of dies or packages. Each RF (radio frequency) port is connected to a test port of the test system. This test approach has several disadvantages. The probing must be done at millimeter wave frequencies and the number of antenna ports (16-36, . . . ) for beam steering devices and multiple input multiple output (MIMO) devices (4+4, . . . ) have to be connected during the test. Moreover, for devices with beam steering capabilities, the circuits responsible for beam steering must be tested (e.g. phase shifters on transmit (TX)/receive (RX) side, uniform gain or path to power amplifier (PA)/from low noise amplifier (LNA)). Therefore, the test time and the efforts in terms of test resources for testing such electronic devices are very high, which also results in enormous test expenditure.